1. Technical Field
The disclosure relates generally to fuel cells, and more particularly to arrangements, including methods, for limiting relative motion between fuel cells in a fuel cell stack.
2. Description of the Related Art
Fuel cells, such as Proton Exchange Membrane (PEM) fuel cells, oftentimes are arranged in assemblies known as fuel cell stacks. In such a fuel cell stack, the fuel cells are oriented one on top of, or next to, another, with the fuel cells being sandwiched between pressure plates. The pressure plates act in compression to longitudinally prevent the fuel cells from separating. Various arrangements exist for facilitating assembly and/or maintaining alignment or registration of the cells in a stack, as exemplified by alignment plugs for facilitating assembly in U.S. Pat. No. 6,423,439; registration inserts and non-identically shaped registration apertures in U.S. Pat. No. 7,297,428; and insulated rods and holes in U.S. Pat. No. 6,620,540.
While the foregoing arrangements are intended to facilitate assembly and/or maintain registration of fuel cells and fuel cell components in a fuel cell stack, further improvement with respect to structure, durability and operability is sought, particularly for fuel cell stacks to be housed and operated in enclosed, human-occupied vehicles where maintaining sealed integrity of the stack under possible operating conditions of extreme vibration and shear loading is of particular importance. One aspect of concern is that the fuel cell stack be protected against slippage, and thus leakage and/or damage to components, which may occur as the result of large shear loads.